time machine versus super duper for bootable backups for macs + pcs

i am told that one cannot easily boot from time machine, and thus many users have both a time machine and super duper backup. i am assuming time machine is for mac only as is super duper.

my set up:
i have a new imac 24" 10.6.2 and i use super duper as i do not need frequent backups. i have a OWC external hard drive. super duper works well, quickly, and fills my needs. i do not use time machine. i have a hard wired ethernet network.

my friends set up
a friend who is using 10.5.8 on a new macbook also has a windows pc using vista. he has a local wi fi network. neither machine has any form of backup except burned dvds of selected files. he is eager to install backup for both machines, but would like to have something that is easy to install and easy to use. he does not need to have minute to minute backups, but he does want to have a bootable back up copy. he could easily use super duper on his macbook, but not sure how to back up the pc.

is there a simple resolution to this? like backup mac on new ext hd using super duper, and independently backup pc on an external hd using some yet to be determined s/w as super duper is not avail for pc.


sorry for the complicated question.

j